I am in the middle of epoxy primer on my Mk1. I have bare metaled the car and it is off to the oven this week. Pros are as stated above it is not like primer and absorbs moisture and the green stuff I am using has a shine to it also so we can see any small dings we may miss with a matt primer finish.
I am filling over the top as I have bubble arched the car and or me it will give a better longer lasting finish.

I ran a welded 4.4 in my old MK1 and snapped 3 shafts and blew the diff out the back of the axle. This was on slicks at Santa Pod but also driving it on the road was ok in the dry but lethal in the wet. As Colr6 said ok on the loose but not much good on the road!

I made my own loom for my pinto mk1 from 7 core trailer cable and put relays and fuse box in,cost me £50 to make. When I cosier it I got a hot rod loom from ezee wiring looms from USA for £85 and this came labelled up ready to fit. Depends how confident you are really?